Furnace structure



July 14, 1931. B. M.'HESS FURNACE STRUQTURE Filed Sept. 6; 1929 5Sheets-Sheet l valley s www,

@Mu m@ July 14, 1931. B. M. HESS 1,814,594

FURNACE STRUCTURE Filed Sept. 6, 1929 5 Sheets-Sheet 2 July 14, 1931. B,M HESS y 1,814,694.

FURNACE STRUCTURE n Filed sept. 6. 1929 5 sheets-sheet s July 14, 1931.B. M. HEss FURNAGE STRUCTURE Filed Sept. 6, 1929 5 Sheets-Sheet 4Ju1y'14, 1931. 1 B. M. HESS 1,814,694

FURNACE STRUCTURE Filed sept. e, 1929 5 sheets-sheet 5 Patented July 14,1931 UNITED STAT BRYGE M. nasser enfonce, ILLINOIS FURNAGE STRUCTURE iApplication filed September Myl invention relatesgenerally` to furnaceVstructures but, morevparticularly, to furnaces forming parts ofapparatuses for drying materials fingeneral by the use of the sproduct'sof combustionof the furnaces directlyapplied'to the material, andespecially tothe drying of grain andthe like. e

One of my objects is to provideimprovements in furnaces torth'eendthatxdanger of.

rcracking of the walls ofthehfurnace through vented. t Y. 4 d Anotherobject is to p'rovidea construction of furnace a large portieri4 of thevwalls of which maybe made ofcommonnonrefractory material' and acomparatively 'small amount of refractory material ber required and'which will not present (danger of the Y, above referred'cracking of itswalls.

lhe exterior surface thereof, `will bev pre- Referring to theaccompanying drawings :L

Figure 2 is an enlargedview in vertical sectional elevation of thefurnace-equipped portionV of the apparatus of Fig. 1, the section beingtaken at the line 2 on Fig. 1 and viewed in the direction of the arrow.y u `Figure 3 isa view in front elevation of 10 the furnace of thepreceding figures.

Figure 4 is asec'tion taken at the line 4 on Fig. '3 and viewed in thedirection of the arrow. f u Figure 5 isa section taken at the'line 5 on1'5 Fig. 4 and rviewed, in the direction of the arrow. i

Figure` 6 is a section taken atthe line 6 on Fig. 4 Aand viewed in thedirection of the arrow.

Figure 7 is an enlarged view in vertical Another object is to provideimprovements e, v192e. serialv No. 390,711.9.V

Sectional elevation of certain of the damperequipped' piping forming apart of the apparatus of Fig. 1.

Figure 8 is a plan section taken at approlii.-

mately the line 8 on Fig. 4 and viewed in the direction of the'arrow;and Figure 9,an enlarged broken section taken at theline 9 on Fig. 8,and viewed in the direction of the arrow.

In thev arrangement shown 8 is a pipe through which theair to be usedfor drying passes to the structure in which the drying operation is tobeteflected'.` The particular construction of such structure of theapparatus is immaterial to the present invention. It may be stated,however, by way of example, that the drying portion of the` apparatusmay be constructed as shown' in United States Letters Patent No.1,210,166 granted to George H. Hess December 26, 1926, and is disclosedand described in my pending application for United StatesLetters FatentSerial No. 378,933,5led July 17, 1929.

The furnace,`the products of combustion fromwhich are to be rutilizedfor the drying purpose, isfrepresented at 9 and comprises a chamber 10in which primary combustion, at

' least, or the fuel supplied thereto, is effected,

the front wall 11 of the furnace Vcontaining fuel inl-et openings 12controlled by doors 13. The bottom of the chamber 10 is in the form of agrate 14 spaced from the bottom of the furnace yto provide a chamber 15opento the atmosphere at its upper portion through an opening 16controlled by a. door 17 hingedly supported at 18, the wall of thechamber 15 at the lower portion of the latter containing openings 19controlled by doors 2O and through which the ashes may be removed.

The yopposite side walls 21 of the furnace contain lowerrearwardly-,extending passages 22 opening through the front of thefurnace and provided' with hingedly-supported doors 23, these passagesopening at their rear ends into the lower end of a vertical passage 24'at the rear of, and substantially coincident vat its upper portionwith, the combustion chamber 10. The lower portion ofthe passage 24 atits central portion is blocked out as represented at 25, this block-ying out portion, which terminates adjacent the grate 14, presentingupwardly converging walls 26, so that the passage 24 is bifurcated atits lower portion, as indicated at 2T at which bifurcation itcommunicates with the rear ends of the passages 22.

' The opposite side walls of the furnace also contain upper passages 28separated from the passages 22 by the partitions 29 and from the passage24 by vertical partitions 30 and open at the front of the furnace atwhich open ends they are equipped with'hingedlysupported doors 31.

The walls of the combustion chamber 10 reach short of the top wall 32 ofthe furnace whereby there is provided a space 33 into which the passages24 and A28 upwardly open, namely, along the rear wall andthe oppositeside walls, respectively, of the chamber l0, the space 33 opening at apoint substantially midway between the front and back walls of thefurnace, into -a flue 34.

The space 33 above the combustion chamber 10 is extended downwardly infront of this chamber as represented at 35 and communicates with apassage 36 in the front wal-l of the furnace and provided with lahandcontrolled damper 3T.

In the arrangement shown the flue `34 opens into an upwardly 'extendingpipehaving ay slide valve 39, the pipe 38 being surrounded by a pipe 40concentric therewith and spaced therefrom this pipe containing series oflouvered openings 4l by which the space between the pipes38 and 40 iscaused to be in communication with the atmosphere. The upper end of thepipe 38 is open and the pipe 40 extends upwardly therebeyond and opensupwardly into the pipe 8 through the bottom wall of the latter. A smokepipe 42 passes through the side of the pipe 40 and opens into the pipe38, the pipe 42 being provided with a hand-controlled damper 43.

In the arrangement shown the pipe 8 communicates at 44 with theatmosphere and means are provided whereby the proportion of hot productsof combustion and diluting air are varied to maintain a predeterminedtemperature in the drying portion of the apparatus.

As the means last referred to form no part of the present invention andare fully disclosed in my said pending application for Letters Patent abrief ydescription thereof will suffice.

The means referred to comprise rotatable dampers 45 located in the pipe40 above the upper end of the pipe 38 these dampers being connectedtogether at levers 46 thereon by a link 47 for simultaneous operation.

The means referred to also comprise a se.- ries of rotatable dampers 48located in the pipe 8 between the dampers 45 and the inlet 44 andconnected together forsimultaneous operation bya link 49 connected withlevers 50 attached to these dampers. The dampers 45 and 48 are connectedtogether for simultaneous movement by a lever 51 connected with one ofthe dampers 48 and a link 52 connected with this lever and one of thelevers 46, the arrangement of parts just referred to being such that asthe dampers 45 move vtoward closed position the dampers 48 move towardopen position, and vice versa.

The damper arangement just described is controlled by thermostaticmechanism eX- tending into the drying portion of the apparatus andcomprising a motor 53 controlled by air pressure supplied to it througha pipe 54 and controlled by the thermostatic device (not shown) in thedrying portion of the apparatus, this motor comprising Va lever 55fulcrumed at 56 and connected withY a link 57, in turn, connected with alever 58 on one of the dampers 45. A spring 59 operates, unlessrestrained, to swingthe lever 55 in a direction for moving the dampers45 to closed position and the dampers 48 to open position. The airpressure in thepipe 54 causes the llever 55 to assume, in opposition tothe tension of the spring 59, the position shown in F ig. l in whichposition the dampers 45 are open and the dampers 48 are closed, when thepressure drops in this pipe, by the rise of temperature in the dryingportion of the apparatus above that at which the thermostatic device isset to operate, the spring 59 operates lto rotate the dampers 45 towardclosed position and the-dampers 48 toward open position; and when thetemperature in the drying portion of the apparatus drops below that atwhich the thermostatic device is set to operateair pressure suppliedvtothe pipe 54 becomes built up therein and moves the dampers 45'towardopen position and the dampers 48 toward closed position.

y The arrangement Valso comprises mechanism fully shown and described inmy said pending application for Apatent for automatically closing thepipe 8 to the passage of air thereto through the inlet 44 and theproducts of combustion and air supplied through the pipes 38 and y40,these means comprising a series of dampers 60 operatively connected withmechanism represented generally at 61 which operates normally to holdthe damper.

60 in open position, but should a temperature condition exist in thedrying portion of thev apparatus rendering it desirable to permanentlyclose the pipe leading thereto, as for example in the case ofspontaneous combustion of the material in the drying apparalus, permitsof the automatic movement of the damper 60 to closed position.

It will be understoodfrom the foregoing that by the arrangement of theair passages in the furnace as described the air flowing into thepassages 22 travels rearwardly to thc back of the furnace and thenceupwardly along the back wall of the combustion chamber 10 and thence`forwardly through the space 33 to the flue 34.-; and the airiowingintothe passages 28 travels` rearwardly and upwardly along the side walls ofthe combustion chamber into the space 33 and thence into the flue 34.

It will further be noted that by the arrangement 0f the air passages asdescribed the lateral walls and the hot portion of the rear wall of thecombustion chamber 10 are separated from the outer walls of the furnaceby ilues t-hrough which the air from the atmosphere flows as stated,with the result of not only maintaining such outer walls in coolcondition and thus not subject to cracking by the heat generated in thecombustion chamber, but conserving the heat of the furnace by absorptionby the air thereby avoiding loss of heat by radiation through the outerWalls of the furnace. Y

The products of combustion discharging from the combustion chamber 10thus become diluted with relatively cold air entering the furnacethrough the passages 22 and 23 and such air as may be admitted throughthe passage 36 and the mixture resulting therefrom discharges into thepipe 38 in a relatively cool condition as compared with the temperatureofthe discharge were it composed whollyA of iot products of combustionissuing from the furnace. Thus the pipe 38 may be made of relativelyinexpensive material such as sheetV Airon without .danger of becomingburnt out and particularly when associated with the surrounding pipe l()through which air from the atmosphere is caused to How by the suction inthis pipeand effect cooling of thev wall of the pipe 38, the pipe 40also serving toreduce radiation of heat from the pipe 38 to theatmosphere by the absorption of heat by the air flowing therethrough andsubsequently mixing with the air and products of combustion issuing fromthe pipe 33.

It will also be noted that the cooling of the products of combustion bydilution with relatively cold air as stated, is effected withoutimpairing the desired combustion of Afuel in the combustion chamber 10as' would be the case were the air for coolingthe hot products ofcombustion introduced directly into the combustion chamber 10.

The damper 37 operates to aid in the controllin of the temperature ofthe mixture of products of combustion and air discharging through theflue 34k and by reason of the adjustable closures 23 and 31 for thepassages 22 and 28, the proportion of products of combustion and airsupplied through these passages for mixture with the products of comofthese outer walls in relativelyV cool condition at' all times, theseouter walls may be built of relatively inexpensive material such ascommon brickor cement Withoutdanger of'cracling, and thus the cost ofrefractory material required to be used informing the partl of thefurnace below the roof thereof, is reduced to the minimum. Economy inthe use of refractory material may be practiced in building theroof ofthe furnace structure as by constructing it as shown ini the drawings..

In theY arrangement shown the ceiling proper and constructed ofrefractory material is suspended from the top, or roof portion, 32, ofthe furnace, the roof portion being made of relatively inexpensivematerial such as common brick or cement,with acentral opening 64therethrough, the wall of which is Vstepped as represented at 65 and 66vand opens into a recess 67 ink the underside of the roof.

Extending acrossthe recess 67 to the front and rear of the opening 64andeach embedded at three sides .thereofV in the roof structure 32, areplates 63 and extending along the ends of these plates and embedded inthe roof structure are angle irons 69, these angle irons being providedon their horizontal flanges withv sets of clips 76 on which I- beams 71extending'crosswise of the furnace and located inthe recess 67, arehung, these beams being thus free to expand and contract Without unduly.stressingv the angleirons 69.

The ceiling proper is formed of rows of blocks 72 of refractory materialwhich are hung on the lower flanges of the I-beams 7l.

The central opening 64E' in the roof is lined with an upper tier ofblocks 73 ofrefractory material flanged at 74 to extend into theystepped portion 65 of the roof proper g` and by a lower tier of blocks75 of refractory material fianged at 76'at which they extend into thestepped rportion 66 of the roof proper and rest upon the free edges ofthe adjacent plates 63, ihe blocks 75 extending close to the uppersurfaces of the adjacent blocks 72 to protect the metal parts ofthe roofstruc? ture from contact With'the products of combustion.

The door 17, provided for controlling the l amount of air supplied tothe fuel in the combustion chamber l() for effecting combustion, ispreferably automatically controlled to diminish the amount of airsupplied to the fuel when the temperature in thedrying por tion of theapparatus reaches a predetermined degree, and to increase the supply o-fair when the temperature drops below such degree; the arrangement shownfor `this purpose being the same as that disclosed in my saidapplication for Letters Patent and compris ing a cable 62 connected atone end with the door 17 and at its other end with the lever 55', theintermediate portion of the cable extending over pulleys 76 and V7 7.

1. A furnace comprising side walls and having a combustion chamber therear wall of which extends in spaced relation to the rear wall of thefurnace providing an upwardlyextending passage, the lateral walls ofsaid furnace containing passages at the sides of said chamber and ofless height than said chamber and communicating vat their rear ends withsaid lirst-referred-to passage below the upper end of the latter;

2. A furnace comprising side walls and having a combination chambertherear wall of which extends in spaced relation 'to the rear wall of thefurnace providing an upwardly extending passage, the lateral walls ofsaid furnace containing passages at the sides of said chamber and ofless height than said chamber connnunicating at their rear ends withsaid first-referred-to passage below the upper end of the latter, thefurnace containing a space above said combustion chamber into Awhichsaid chamberand said first-referred-to passage open and an outletCommunicating with saidzspace.v

3. A furnace comprising side walls and having a combustion chamber theupwardly extending walls of which at its opposite sides and rear portionare spaced from the ones of said side walls which they, respectively,oppose providing a passage at the rear end of said combustion chamberand passages at opposite sides thereof, partitions in saidlast-referred-to passages dividing the latter at each side of thefurnace into upper and lower passages open to the atmosphere, the

lower ones of which open into said first-re-v ferred-to passage belowthe upper end of the latter, the furnace containing a space open to thecombustion chamber and to the passage at the rear of said combustionchamber and to said upper passages and also containing a luecommunicating with said space.

4l. A furnace comprising side walls and having a combustion chamber therear wall of which extends in spaced relation to the rear wall of thefurnace Vproviding an upwardly extending passage, the lateral walls ofsaid furnace containing passages at the sides of said chamber and ofless height than said chamber and communicating at their rear ends withsaid first-referred-to 'passage below the upper end of the latter andopen to the atmosphere, said furnace also having passages at oppositesides of said chamber above said second-referred-to passages and open tothe atmosphere, and said furnace containing a space above saidcombustion chamber into Awhich said chamber and said firstnamed passageand said last-named passages open.

BRYCE M. HESS.

